import time
def maxsquare(x,y):
    print(x,y)
    yu = x%y
    if yu == 0:
        return yu
    else:
        return maxsquare(max(x-y,yu),min(x-y,yu))

print(maxsquare(1680,640))

print(time.strftime("%H_%M_%S", time.localtime()))
